Wiper blade

ABSTRACT

A wiper blade for cleaning motor vehicle windows has a wiper strip ( 12 ) which is surrounded by a guard profile ( 14 ) that with extensions ( 26, 28 ) formed onto its side cheeks ( 22, 24 ) engages longitudinal grooves ( 50, 52 ) of the wiper strip ( 12 ) and is fixed axially on the wiper strip ( 12 ) by inward-protruding protrusions ( 30, 32 ) in the region of its face ends ( 18, 20 ). The protrusions ( 30, 32 ) originate at one side cheek ( 22, 24 ) of the guard profile ( 14 ), and a first protrusion ( 30 ) extends on the outer face end ( 18 ) of the guard profile ( 14 ) to touch the opposite side cheek ( 22, 24 ) of the guard profile ( 14 ), while a second protrusion ( 32 ) on the inner face end ( 20 ) forms a gap ( 38 ) from the opposed side cheek ( 22, 24 ), which the gap allows mounting or unmounting of the guard profile ( 14 ) in the longitudinal direction ( 40, 42 ).

BACKGROUND OF INVENTION

The invention is based on a wiper blade.

Known windshield wipers for motor vehicles have a wiper arm, which isconstructed of a fastening part, fastened to a drive shaft; a hinge partconnected to it via a toggle joint; and a wiper rod rigidly adjoiningthe hinge part. A wiper blade with a wiper strip is pivotably connectedto the wiper arm and guided over a motor vehicle window; the hinge partand the wiper blade are embodied such that the wiper strip can adapt toa curvature of the motor vehicle window. A requisite contact pressure ofthe wiper strip on the motor vehicle window is achieved with at leastone tension spring, which braces the fastening part and the hinge partjointly with the wiper rod, via the toggle joint.

The wiper strip comprises an elastomer, such as a natural or syntheticrubber, or ethylenepropylene. It has a head strip, which via a tiltingrib located between two longitudinal grooves is joined to a wiper lipresting on the vehicle window. By means of the tilting rib, the wiperlip at the turning point of the wiper motion can fold over in theopposite direction, so that it always assumes a favorable positioningangle relative to the windshield. If the windshield wiper is actuated,the wiper strip with the wiper lip slides over the motor vehicle window,and it wears down from friction between the wiper lip and thewindshield. Environmental factors also affect the wiper strip, such astemperature fluctuations, UV radiation, saltwater, exhaust gases, and soforth, which can lead to premature aging of the material and increasedwear.

To assure that when a new motor vehicle is shipped the wiper strip is inperfect condition, it is known from German Patent DE 30 05 965 C2 tocover the wiper strip with a guard profile before the motor vehicle isput in preservative. The guard profile is not removed until the newmotor vehicle, after the preservative is removed, is handed over to abuyer. The guard profile has two side cheeks extending in thelongitudinal direction, on which shoulders are formed that engage thelongitudinal grooves on both sides of the tilting rib of the wiperstrip. To enable cleaning the vehicle window so that the motor vehiclecan be maneuvered, if the vehicle window during temporary storage of themotor vehicle or in the sealing process and so forth becomes soiled orthe view is obstructed by rain, the guard profile has a wiper lip on itsouter contour. As a rule, the guard profile comprises a suitableplastic.

To fasten the guard profile in such a way that it cannot be lost fromthe wiper blade and to protect the wiper strip on its face end fromenvironmental factors, it is also known to weld the guard profile on theface end. To that end, the guard profile is heated on the lateral faceends and pressed against a plate. This creates a plate of material thatcloses off the guard profile. Before mounting, only one face end can bewelded. If the second face end is welded after the guard profile hasbeen slipped onto the wiper strip, then the guard profile has to be cutopen for unmounting, which destroys it so that it cannot be used again.

From German Patent Disclosure DE 44 10 446 A1, a similar guard profileis also known, which for axial securing to the wiper strip hasinward-pointing evulsions in the extensions in the region of the faceends. The evulsions block a longitudinal displacement of the guardprofile, and their height is dimensioned such that they cannot penetrateinto the longitudinal grooves. They are produced by drawing, forinstance by ball upsetting.

In the earlier German Patent Application DE 199 35 858.3, a guardprofile is described which has inward-pointing protrusions on its endsthat originate at the side cheeks and extend either as far as theopposite side cheek or form a gap from the side cheek that allowsmounting on a wiper strip. The protrusions can be combined with otherclosures for the face ends, such as a cap or a welded face end. Theguard profile is fixed axially to the wiper strip by the closures orprotrusions.

SUMMARY OF THE INVENTION

According to the invention, the protrusions originate at one side cheekof the guard profile, and a first protrusion extends, near the outerface end of the guard profile, to close to the opposite side cheek ofthe guard profile, while a second protrusion near the inner face endforms a gap from the opposed side cheek, which gap allows mounting orunmounting of the guard profile in the longitudinal direction. Theprotrusions can be made quickly and simply, for instance in the case ofmetal guard profiles with a kind of tongs or plastic profiles with aheat source, especially an ultrasonic source by means of an ultrasoundprobe.

Upon a pivoting motion of the windshield wiper over a vehicle window,force components that are especially pronounced if the vehicle window isdry or quite dirty or in wiper systems with four-bar control or areciprocating gear act on the guard profile in the axial direction. In afour-bar control or reciprocating gear, the pivoting motion of thewindshield wiper has a reciprocating motion superimposed on it, in orderto increase the size of the swept field. However, in that case, majorforces are exerted axially on the wiper blade. These forces tend todisplace the guard profile in the direction of the inner circle, thatis, the inner face end, of the wiper blade. Depending on the magnitudeof the axial forces, the closures on the outer face end of the guardprofile, if they are suitable for unmounting, experience excessivepressure. As a consequence, the guard profile creeps inward. Thisseverely impairs the outcome of wiping, and part of the wiper strip,which is to be protected, of the windshield wiper is laid bare.

The wiper blade of the invention has a guard rail, which on the outerface end is closed by a protrusion extending transversely to theopening; this protrusion originates at one side cheek and extends as faras the opposite side cheek of the guard profile. This closure does notallow mounting or unmounting. As a result, it is assured that even undermajor axial forces the guard profile cannot creep inward. Nevertheless,it can be mounted and unmounted via the inner face end that has less ofa load on it, so that it can be re-used multiple times.

Expediently, the length of the protrusions decreases in the direction ofa wiper lip that is provided on the outer contour of the guard profile.Thus the protrusions essentially follow the inner contour of the sidecheeks, so that the first protrusion can closely adjoin the opposed sidecheek, and the gap between the second protrusion and the opposed sidecheek remains virtually constant in width. The second protrusion has aninclined chamfer relative to the mounting direction, which chamfer, inthe mounting process orients the wiper lip of the wiper strip toward thegap. This greatly simplifies mounting of the guard profile. To makeunmounting easier as well, the second protrusion has an inclined chamferrelative to the unmounting direction, which chamfer, in the unmountingprocess orients the wiper lip of the wiper strip toward the gap.Expediently, the chamfer operative in the mounting direction, with across-sectional plane forms a larger angle than the chamfer operative inthe unmounting direction, since the chamfer operative in the unmountingdirection must during wiping operation assure a secure fixation of theguard profile with respect to outward-acting axial forces.

To assure the correct mounting of the guard profile in an automatedmounting apparatus as well, it is expedient that the first protrusionsdiffer in form, in particular in cross section and/or longitudinalsection, from the second protrusions. As a result, the inner and outerends of the guard profile can be identified simply and reliably.Moreover, the various protrusions can each be provided on different sidecheeks of the guard profile.

The protrusions can be made quickly and simply, for instance in the caseof metal profiles with a kind of tongs and in plastic profiles with aheat source, in particular an ultrasonic source by means of anultrasonic probe; advantageously, the first protrusions on the outerface end of the guard profile can be welded to the opposed side cheek.This enhances the strength and shape stability, in particulartransversely to the side cheeks in the critical end region.

BRIEF DESCRIPTION OF DRAWINGS

Further advantages will become apparent from the ensuing drawingdescription. In the drawing, one exemplary embodiment of the inventionis shown. The drawing, description and claims include numerouscharacteristics in combination. One skilled in the art will expedientlyconsider the characteristics individually as well and put them togetherto make useful further combinations.

Shown are:

FIG. 1, a fragmentary view of a wiper blade;

FIG. 2, an enlarged fragmentary view of the ends of a guard profiletaken along the line II in FIG. 1;

FIG. 3, a section taken along the line III—III in FIG. 2;

FIG. 4, a section taken along the line IV—IV in FIG. 2;

FIG. 5, a section taken along the line V—V in FIG. 2;

FIG. 6, a section taken along the line VI-VI in FIG. 2; and

FIG. 7, a section taken along the line VII—VII in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The wiper blade 10 is pivotably connected to a wiper rod 16 of a wiperarm, not shown in further detail, and has a wiper strip 12 that issupported by a support bracket system 60. Instead of the support bracketsystem 60, a bracketless supporter can also hold the wiper strip 12, andbecause of its elasticity can adapt to the curvature of a vehiclewindow.

The wiper strip 12 is joined by means of its head strip 44 to thesupport bracket system 60. The head strip 44 is adjoined via a tiltingrib 48 by a wiper lip 46. The tilting rib 48, which is bounded by twolateral longitudinal grooves 50 and 52, allows the wiper lip 46 tochange its positioning angle to the vehicle window, at the turningpoints of the pivoting motion, to suit the wiping direction.

To protect the wiper strip 12 and in particular the wiper lip 46 beforea new vehicle is shipped, a guard profile 14 is slipped onto the wiperstrip 12 from an outer face end 18 in the mounting direction 40. Theguard profile 14 has two joined-together side cheeks 22 and 24, whichare adjoined by extensions 26 and 28 that engage the longitudinalgrooves 50 and 52. On the outer contour of the guard profile 14, in theregion where the side cheeks 22 and 24 meet, a wiper lip 34 is provided.The wall thickness and shape of the side cheeks 22 and 24 is selectedsuch that the wiper lip 34 can adapt elastically to a certain extent tothe curvature of the vehicle window.

In the region of the outer face end 18 and an inner face end 20, theguard profile 14 has protrusions 30 and 32 on its ends; the protrusionseach originate at a respective side cheek 22 and 24 and extendtransversely through the interior of the guard profile 14. A firstprotrusion 30 in the region of the outer face end 18 originates at theside cheek 22 and extends to close to the opposed side cheek 24. It canalso touch the side cheek 24 and be welded to it. On the other end ofthe guard profile 14, a second protrusion 32 is provided in the regionof the inner face end 20. This protrusion originates at the side cheek24 and extends toward the opposite side cheek 22, with which it forms agap 38 that allows mounting and unmounting of the guard profile.

If the guard profile 14 is slipped by one end, which has the secondprotrusion 32, onto the wiper strip 12 in the mounting direction 40, thewiper lip 46 of the wiper strip 12 moves through the gap 38 past thesecond protrusion 32, until the end of the guard profile 14, with thefirst protrusion 30, rests on the end of the wiper strip 12. In thisposition, the wiper lip 46 of the wiper strip 12 resumes its originalposition, so that the wiper strip 12 is axially fixed between theprotrusions 30 and 32.

To facilitate mounting, the second protrusion 32 has a chamfer 56,inclined in the mounting direction 40, which has an angle ofapproximately 30° from a cross-sectional plane 58. In the unmountingdirection 42, the second protrusion 32 has a further chamfer 54. Thischamfer 54 forms an angle of approximately 10° with the cross-sectionalplane 58. This angle is dimensioned such that on the one hand it allowsgood unmounting of the guard profile 14 and on the other assures securefixation of the guard profile 14.

The guard profile 14 can be made from sheet metal. Expediently, however,it comprises an extruded plastic. In that case, it is expedient to makethe protrusions 30 and 32 with an ultrasonic probe; the length 36 of theprotrusions 30 and 32 decreases in the direction of the wiper lip 34, sothat the protrusions 30 and 32 extend essentially parallel to theiropposed side cheeks 22 and 24. As a result, the possibility exists inthe region of the first protrusion 30 of welding this protrusion over alarge area to the opposed side cheek 24, while in the region of thesecond protrusion the gap 38 has a virtually constant width.

What is claimed is:
 1. A wiper blade (10) with a wiper strip (12), whichis surrounded by a guard profile (14) that with extensions (26, 28)formed onto its side cheeks (22, 24) engages longitudinal grooves (50,52) of the wiper strip (12) and is fixed axially on the wiper strip (12)by inward-protruding protrusions (30, 32) in the region of its face ends(18, 20), characterized in that the protrusions (30, 32) originate atone side cheek (22, 24) of the guard profile (14), and a firstprotrusion (30) extends on an outer face end (18) of the guard profile(14) to be close to the opposite side cheek (22, 24) of the guardprofile (14), while a second protrusion (32) on an inner face end (20)forms a gap (38) from the opposed side cheek (22, 24), so that the gapallows mounting or unmounting of the guard profile (14) in alongitudinal direction (40, 42).
 2. The wiper blade (10) of claim 1,characterized in that the length (36) of the protrusions (30, 32)decreases in the direction of a wiper lip (34) of the guard profile(14), and the gap (38) is virtually constant in width.
 3. The wiperblade (10) of claim 1, characterized in that the second protrusion (32)has a chamfer (56), inclined in a mounting direction (40), which in themounting process orients the wiper lip (46) of the wiper strip (12)toward the gap (38).
 4. The wiper blade (10) of claim 1, characterizedin that the second protrusion (32) has a chamfer (56), inclined in aunmounting direction (42), which in the unmounting process orients thewiper lip (46) of the wiper strip (12) toward the gap (38).
 5. The wiperblade, (10) of claim 1, characterized in that the second protrusionsuited to has a chamfer (56) operative in a mounting direction (40),with a cross-sectional plane (58) forms a larger angle than a chamfer(54) operative in an unmounting direction (42).
 6. The wiper blade (10)of claim 1, characterized in that the first protrusions (30) differ incross section and/or longitudinal section from the second protrusions(32).
 7. The wiper blade (10) of claim 1, characterized in that theguard profile (14) comprises plastic, and at least one protrusion (30,32) is made with an ultrasonic probe.
 8. The wiper blade (10) of claim7, characterized in that the first protrusion (30) is at least partlywelded to the opposed side cheek (22, 24).